US Patent 7422569 Vasoocclusive coil with enhanced therapeutic strand structure

A vasoocclusive coil is reinforced with a stretch resistant member to improve safety during retraction of the coil. The stretch resistant member is fixedly attached at one end to the vasoocclusive coil, and the other end of the stretch resistant member is detachably mounted to an elongated pusher member to allow for placement and release of the vasoocclusive coil within the patient's vasculature. The stretch resistant member may be formed from a therapeutic and/or bioactive non-metallic material to enhance the therapeutic properties of the vasoocclusive coil.